The present invention relates to a system for regulating the idling speed of rotation of an internal combustion engine, in which a correction variable, determined by comparison of the actual speed of rotation which is fed as speed-of-rotation signal with a desired speed-of-rotation value, is fed to a control member.
In the known systems for regulating the idling speed of rotation of an internal combustion engine, the control member, which is arranged in a so-called bypass on the throttle valve, is opened wide when the internal combustion engine is cold, in order for a sufficiently high idling speed of rotation to be obtained. With the same opening of the control member one obtains, however, when the engine is hot, a speed of rotation which lies outside of the idling speed-of-rotation range which is permissible based on considerations of safety. If the speed-of-rotation signal drops--due, for instance, to a break in the conduit or a short circuit of the transmitter--then too low a speed of rotation will be simulated, whereupon the regulator opens the control member wide, which leads to too high an idling speed of rotation when the engine is hot.